This invention relates to devices for use with agricultural implements. More specifically, the invention relates to a caddy equipped with a guidance system for towing agricultural implements used in row crop farming. The tractor drawn caddy converts mounted implements to pull-type and the related guidance system automatically corrects the path of travel for the caddy to prevent the wheels on the caddy and the ground-engaging attachments on the implement from drifting away from their preferred positions between the rows of crop. The invention offers both a technological advantage to the farmer/user as well as a significant reduction in overall equipment costs.
Many agricultural implements such as cultivators, planters and the like are built to be pulled by a tractor. Such implements are bulky, requiring some mechanism to prevent the ground-engaging attachments of the implement from drifting significantly from their preferred position between the rows of crop. As is known to those skilled in the art, some correction is provided by the use of a three-point hitch wherein the two diverging draft links provide a limited degree of self-correction for the problem of implement drift. However, the conventional three-point hitch still allows implement drifting to occur, and has failed to completely prevent the implement attachments from drifting into the individual crop rows. Notwithstanding the use of the three-point hitch, crop damage can occur when the tractor operator inadvertently steers into the crop, for example, with the implement following therebehind. Moreover, the operation of the aforementioned equipment on hilly terrain, such as on side hills, makes the problem of crop damage more serious since both the tractor and the implement tend to slide downhill, requiring a highly skilled tractor driver to compensate by steering the tractor slightly uphill so that the tractor and the attached implement move forward on a slight skew. These and other problems have made the three-point hitch less than satisfactory for controlling implement drifting in row-crop farming.
For more enhanced control, electronic guidance systems have been developed and typically include at least one sensor mechanism to detect the position of the implement relative to the crop rows. Any deviation from the desired lateral position of the implement relative to the rows of crop is detected and a steering mechanism is activated to reset the path of travel in an attempt to maintain the implement attachments between the rows of the crop. These guidance systems can be passive or can operate automatically and offer an additional means for correcting implement drift during field operations. Yet, these guidance systems, while providing some advantages over the three point hitch in correcting implement drifting, have generally been unsatisfactory in their operation. Moreover, these systems have generally been expensive and compatible only with larger (and more expensive) equipment such as more powerful tractors (e.g. 175 horsepower). Consequently, the guidance systems of the prior art have failed to effect any reduction in overall equipment costs and, while providing some drift-correcting ability, have been less than satisfactory in those applications where implement drift becomes more severe, such as on hills or uneven terrain and especially on side hills with slopes of about 20% (20 feet of rise for every 100 feet travelled).
In light of the shortcoming and limitations of the prior art, it is desirable to provide a guidance control system to automatically control the positioning of an implement within the rows of a crop, allowing the farmer or tractor operator to concentrate on his or her driving without constantly having to visually monitor the position of the implement within the rows. It is also desirable to provide such a guidance system along with a device which will effectively convert a larger implement such as a sixteen-row cultivator, for example, from a mounted implement to a pull-type implement, allowing the farmer to use a smaller tractor (e.g. 60 horsepower) and thereby providing a significant reduction in equipment costs. Most preferably, such a device should be capable of steering a towed implement in a manner that is at least partially independent of the position of the tractor and which will operate with improved steering abilities on rough, uneven and hilly terrain.
The present invention provides such a desired apparatus and overcomes the aforementioned limitations of the prior art by providing a caddy to convert mounted implements to pull-type, allowing larger implements to be pulled by smaller tractors while simultaneously providing a guidance system therewith to maintain the ground-engaging attachments associated with the implement between the crop rows. The apparatus of the present invention includes a caddy which can be pivotally attached to a tractor. The caddy includes a frame assembly and a load-carrying axle mounted for rotation about a vertical axis at the rear of the caddy. A three-point hitch is provided in association with the rear axle for attachment to a mounted implement. A guidance system is provided as a sensor-activated hydraulic mechanism wherein two opposed hydraulic cylinders are mounted along the frame of the caddy and attached to the rear axle thereof to displace the axle by a pivoting action about the aforementioned vertical axis and thereby steer the caddy to maintain the implement in a desired lateral position with respect to the crop rows.
The sensor assembly of the guidance system includes a pair of sensing wands extending down from the frame of the caddy so that each wand is positioned along the adjacent row of crop when the implement tools are positioned appropriately within the center of the row. The wands are connected to a first sensor. If the implement begins to drift significantly from its desired position within the rows, one of the sensor wands will engage the adjacent row of crop more solidly than the opposite wand and this deviation will be translated into an electrical signal picked up by the first sensor. The sensor will then actuate a hydraulic circuit to rotate the rear axle and the implement about the vertical axis in a direction away from the crop row which was engaged by the wand, turning the rear axle of the caddy toward the center of the crop row.
A second or feedback sensor is also provided to generate a signal when the rear axle is rotated to make the above-discussed correction. The feedback sensor will actuate the hydraulic cylinders again when the implement is returned to the desired path and rotate the axle back to a transverse position relative to both the crop rows and the direction of travel.
It is accordingly an object of the present invention to provide a device that can be used in row crop farming with conventional row crop implements.
It is also an object of the present invention to provide a caddy with a guidance system which allows for the conversion of mounted implements into pull-type implements and wherein the guidance system of the invention automatically corrects the position of the caddy and implement to maintain a desired position in the crop rows.
Other objects, features and advantages of the present invention will be apparent to those skilled in the art upon consideration of the remainder of the disclosure.